A British soldier killed in an explosion in southern Afghanistan on Remembrance Sunday is expected to be named.

The serviceman, from 1st Battalion The Royal Irish Regiment, was caught in a blast while out on patrol in the Nad'e Ali area of Helmand province on Sunday morning.

His death came as Prince William flew into Camp Bastion with Defence Secretary Liam Fox for a poignant service of remembrance.

Spokesman for Task Force Helmand, Lieutenant Colonel David Eastman, said: "It is with a heavy heart that I must report the loss of a soldier from 1st Battalion The Royal Irish Regiment.

"The soldier was part of a patrol providing security and a reassuring presence for the people of Nad'e Ali when he was hit by an Improvised Explosive Device.

"On this day of all days, his loss feels especially poignant and, as with all of our brave, fallen comrades, will be forever marked in our thoughts; he will be sorely missed."

Northern Ireland First Minister Peter Robinson said he was deeply moved and saddened by the Co Londonderry soldier's death.

"This death brings home the reality of war. Remembrance Sunday is not about the past, it's about the present," he said.

"It's about the family in Northern Ireland who are now grieving the loss of their boy. I extend my deepest sympathies to them."

Ulster Unionist Party leader Tom Elliot said: "It is with great sadness that I have learnt of the death in Afghanistan of a young soldier from the Royal Irish Regiment. Brave young men and women in Northern Ireland have given their lives to protect us and our freedom and even on the day that we remember them, one more hero has given his life."